Product Overview

The radiator cap, OEM number 55116901AA, seals the cooling system and keeps it under pressure, which raises the boiling point of the coolant and helps the engine run at a stable temperature. It opens and closes with every heat cycle, so its spring and rubber seal wear over time, which makes it a low-cost, high-volume replacement item in the cooling system category.

A weak or leaking cap can cause coolant loss and overheating, so a cap that holds pressure reliably matters. GSK Auto manufactures this radiator cap to OEM specification at our Ningbo, China facility, with every unit tested before packing. We supply at wholesale volume with low MOQ and support private label packaging, with our team available to confirm the OEM number match before shipping.

Replacement OEM Numbers

Cross-Reference OEM Number

52079799AA

What Is a Radiator Cap?

Function: The radiator cap closes the radiator filler neck, holds the cooling system at its rated pressure, and releases excess pressure or lets coolant flow to and from the overflow reservoir when needed.

Working Principle: A spring-loaded pressure valve opens when system pressure goes above the cap's rating, letting coolant escape to the reservoir. A vacuum valve opens as the engine cools, drawing coolant back in so the system does not collapse.

Importance: Pressure raises the coolant's boiling point, so a good cap helps prevent boil-over and overheating. A failed cap can lose coolant or let pressure drop, reducing cooling efficiency.

Common Failures & Signs: Engine overheating or coolant boiling over. Coolant leaking around the cap or filler neck. Coolant level dropping in the reservoir. Swollen or collapsed radiator hoses. Cracked, worn, or hardened rubber seal, or a weak spring.

Key Features

OEM-standard fitment - matches factory size, seat design, and locking fit for the OEM 55116901AA application.

Reliable pressure control - built to hold and release pressure at the specified rating.

Durable seal - heat-resistant rubber built to keep a tight seal through repeated heat cycles.

Direct replacement - installs in place of the original cap, matched by OEM number.

Tested before shipment - every unit checked before packing.

Benefits

Importers - covers radiator cap demand from a single sourcing partner.

Wholesalers - a low-cost, high-turnover item in the cooling system category.

Repair Shops - tested units reduce comeback risk on a common overheating repair.

Distributors - private label packaging available for building a branded catalog.

Packaging & Shipping

Standard export cartons. Customized packaging available for distributor branding. OEM-style and private label printing on request. Container loading handled directly, with mixed-SKU consolidation for smaller orders. Worldwide shipping to Europe, North America, South America, the Middle East, Africa, and Southeast Asia.

Why Choose GSK Auto

GSK Auto manufactures factory-direct, keeping pricing tied to production cost. This radiator cap is built to OEM specification and tested before packing. We support low MOQ, private label packaging, and worldwide shipping, with our technical team available to confirm the OEM number match before you order.

Call to Action

Sourcing radiator caps by OEM number? Contact GSK Auto for a wholesale quote, catalog, or OEM/private label cooperation.